Metastatic renal cell carcinoma has been considered to be resistant to chemotherapy, with responses observed in only limited numbers of patients. For this reason, therapeutic options have ranged from no treatment, to immunotherapy with cytokines such as IL-2 and interferon-alpha, chemotherapy alone or in combination with cytokines, and to a variety of new investigational approaches. Interferon and interleukin-2 (IL-2) have led to long-term survival in selected patients. Immunotherapy with cytokines, monoclonal antibodies, new agents, dendritic cell therapy, and allotransplantation offer promise. Novel therapeutic strategies include combining cytokines, and antiangiogenic approaches such as thalidomide and antivascular endothelial growth factor therapy. Pathologic, cytogenic and molecular studies have proven that renal cell carcinoma is not a single tumor entity. Efforts to improve results also include the identification of prognostic factors, which allow treatment to be better directed towards those patients most likely to benefit. Increasing understanding of cancer biology is beginning to allow for a more targeted approach to the therapy of metastatic renal cell carcinoma. Adequate positioning of known treatments is essential and many trials of new targeted therapies are underway.
